Five days into the 6g Amano tank, I'm learning all kinds of things about CO2 and its influence on water chemistry. I've been working with a DIY CO2 source combining sugar water and yeast in a 2 litre Coke bottle.

Four days of chemistry readings show that the CO2 struggles to stay above 4 ppm but sometimes reaches 6 ppm. Desirable range is 5 to 15 ppm, so I'm skirting the low end.

Most important lesson is that tweaking and maintaining a yeast-based CO2 source will be the death of me. I have to adjust the yeast content, swirl a couple of times a day. I knew this would be a high-maintenance tank, but that kind of attention is really pushing it. So...

I bought a couple of pricey accessories today. The first is a CO2 solenoid regulator, the second is a 2.5 lb. CO2 tank. The tank is on its way from San Diego and should arrive early next week. The regulator, which includes a bubble counter, will attach to the CO2 tank. The silicone tube from the Vortex Reactor currently in the aquarium will connect to the regulator. Voila, much improved CO2 injection, much less maintenance. The CO2 tank will yield a few months of CO2, far tastier a solution than replacing a yeast source every week.

I also purchased several water controllers and plant supplements. I had been concerned about the zero KH readings. Plants want a certain level of carbonate hardness, so I bought two products to boost GH and KH, plus iron, potassium, and micronutrients to feed the plants.